I’d noticed a while back that the bolts at the back of both exhaust manifolds were both missing their heads. The manifolds weren’t leaking so I decided not to worry about it. During our trip to Trail and back I noticed the sound of an exhaust leak. Also, for a while performance seemed to have declined.
When I got back home I pulled off the doghouse and sure enough there was now soot around the area I suspected was leaking. When I revved the engine there were also puffs of black smoke visible on both sides.
Foolishly I started on the passenger side that has about an inch between the exhaust manifold and the inner fender and spring tower. After a great deal of effort and abuse of my 1/4” drive sockets, I somehow managed to remove and reinstall that manifold and up-pipe to the turbo.
I’d ordered new manifold bolts and gaskets, but couldn’t find the up-pipe bolts sold separately from the up-pipes. I’d tried Napa, Lordco, and Suburban motors… they were either not listed and/or NLA. I called Wilson & Proctor and they were going to look into it and call me back, but it didn’t sound promising. I was at Fastener force when W & P called back. Fastener force had the Metric shoulder bolts for $3 each but didn’t have shouldered nuts in the grade 10.9. W & P had bolts for $23 each and nuts for $3 each. So I bought the bolts at Fastener Force and the nuts from Wilson & Procter.
It turns out that the shouldered nuts were also self locking by being just slightly oval at the small side. The mechanic at W & P said the OEM up-pipe bolts were also heat treated… but for $80 less I decided to risk the grade 10.9 bolts from Fastener Force would be strong enough. Part of my logic being that if the up-pipes to the turbo are leaking after the gaskets are installed (between the exhaust manifolds and the block) I’ll be replacing the Ford up-pipes with billowed International up-pipes that come with new bolts.
Apparently when Ford decided to stuff a 7.3 (455) into an E350, they moved it an inch or so to the passenger side to have space for the steering box. This meant that there was 3(or so) inches between the manifold and the frame. Whereas on the passenger side there was no space to work, the driver’s side had plenty. Plenty is no space compared to an Fj40 (even with a 350). But a couple extra inches made it way easier.
The driver side manifold after removal.
Evidence that the top of the crossmember under the engine isn’t nearly as clean as areas that can normally be reached.
Before putting the second manifold I did back out the broken bolt and put in an intact one. Unfortunately, it had been driven for too many years without that bolt and the cast block no longer sealed to the cast iron manifold without a gasket.
Now that both exhaust manifolds now have gaskets, the exhaust leaks are resolved. I hadn’t noticed, as the leak gradually got worse over the last 9 years, that I was no longer hearing the turbo spool up and down like it used to. Now with the leaks fixed I am hearing the turbo again… and I can also feel the extra torque as it spools up.
Next up is seeing if I can find replacement bushings for the OEM up-pipes or billowed pipes that fit a rectangular flanged turbo. A
When the engine is cold I can feel a very small amount of airflow around the up-pipe that I removed during the gasket install. There is no visible soot coming out, but any exhaust gases escaping would mean less pressure getting to the turbo. For now I’ll keep an eye on it and see if it gets better or worse.
